New Garden Shed Build

With the weather looking good for the next week, I've decided to take the plunge and dismantle the old rotten shed from the bottom of the garden.

The current shed is a good size at approx. 3x2.5m, however there is so much wasted space around it, I'd like a much larger 3x4m or 4x4m workshop (man shed), something sturdy and insulated rather than a traditional shed.

Today, I've dismantled the old roof, with intent to fully demolishion tomorrow. Once the ground is clear, I hope the size/shape of a new shed will become clearer.



As a guide, I looked at the local shed companies who's prices for this size range between £1.5-£3k. Never afraid of a challenge (famous last words), I'd like to think I could build my own and to a higher spec for around £1000 (or less?)

The location is the darkest and wettest part of the garden - the ground is also very uneaven, has a large tree lined bank to the rear, and accessible only by foot. Considering these attributes, I wish to design and build something capable of better withstanding the elements than the old timber shed.

Question 1:
The base will need to be raised, but undecided on the most appropriate method. I was wondering if anyone could share some pearls of wisdom in this regard. So far I have watched videos with sheds built direct onto leveled blocks (with varying degrees of success), an interesting solution from a UK garden room building firm using steel rods set in concrete, and an unrealisticly expensive solution using something called Groundscrews.

Question 2:
As the location is so wet, instead of timber cladding and a felt roof, I'm considering alternative longer lasting / low maintenance methods of roofing and cladding. Featheredge timber aside, what methods are worth considering? I'm currently looking into coated box profile metal sheeting - however costs could become a deciding factor.

Thanks.

 

Update:
Because the access is tight I couldn't remove the side panels complete, I've had to remove the cladding, back to the framework. It took so long, I only managed 75%. So today, I should get the last off and take up the floor.



Base Questions:
@JWK @Loofah - I've started researching how to best lay dense concrete blocks and have to agree, it seems the most sensible / cost effective. A full concrete slab is not really viable in this location.

You mention concrete footings or pads. Are you suggesting I dig deeper holes - fill each with concrete up to the same level… then place a concrete block onto each + DPM before any timber work? (I expect there to be a considerable height difference between the highest and lowest parts).

Most examples that I find (via good DIYers on YouTube), are situated on reletively level ground. They generally dig holes to approx 6" depth, back fill with gravel and site the blocks on top. Blocks are raised with either a little more gravel or additional blocks or slates to find the level. I've rarely seen examples of poured concrete - and when I have they seem to be for larger heavy constructions.

Roofing and panelling:
Thank you all for steering me away from metal panels. Keeping the contents of the workshop dry is highly important, so definitely don't need any unwanted condensation.

If cladding in wood, what would you recommend as the best / cost effective option?… Should I be relooking at Featheredge boards?

As an alternative roofing option, I remembered yesterday that I have 40 x (600x300) roof slates and roll of breathable membrane left over from our previous house. I'm wondering about finishing the roof with these instead? (I'm really not a fan of felt - even good quality ones).

@Fat Controller I heard the price of wood has increased over lockdown. Fortunately I will be utilising a garage full of timber from previous projects, but will still need to buy most of it. I'd rather pursue the self build route as I enjoy a good challenge and that sense of achievement from building something.

 

I've just had my conservatory reroofed with Tapco slates.
They are plastic and light weight.
Minimum pitch for these is 14 degrees.

 

I was hoping the site would be clear, but it took all day to fully removed side panels and take everything to the tip. I still have the old base to take up, which I hope to do today/tomorrow with a view to having the ground clear.

Thanks again for more advice. I’m positive, the block pads is absolutely the right solution. I’m sure the weight of the proposed workshop will be significant, so think using dense blocks is the right in this instance. While it can be wet and rainy here, the building is well sheltered from the wind by surrounding trees etc.

Beneath the shed, I will also be installing a suitable weed barrier and suitable preventative mesh designed to stop badgers borrowing under (neighbours told me this has happened in the past).

I researched the useable pitch of the tiles - unfortunately they require a minimum angle of 17.5º to be effective. I’m planning a pent roof design (highest edge at the front, sloping down to the rear), so drew a rough side elevation to better understand the pitch and effects . Assuming the shed has a depth of 3.5m and max legal height of 2.5m, it will need a 5º pitch (max) to provide a decent internal head room (2m at the front - 1.75m at the rear).

As for the side panels - 20mm timber shiplap seems to be the way to go.

 

Another vote for shiplap instead of featheredge. The end result is simply better in every way - looks neater, takes wood treatments better, lasts longer, and doesn't give big gaps between planks as it ages. It costs a bit more, but it sounds like you're more concerned about quality than price.

 

Surely feather edge is fencing material???